The shape layer method would be to use the Star Shape to create a star shape layer. Animate the scale from 0% to whatever you need to cover the entire screen in the amount of time you want for the wipe to occur. Place the video layer you want to star wipe on, below the star shape and change it's track matte to Alpha matte.

Johnny Cuevas, Editor
Thinkck.com

"I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."
---THOMAS EDISON on inventing the light bulb.